Lysine diisocyanate or L-lysine ethyl ester diisocyanate

LDI (Cas 45175-15-4) is a versatile material that can be processed in biomaterials to result in non-toxic biodegradable polymers/ matrices. Our high purity material ensures a high quality end material.

Biodegradability – Biomedical applications Ester L-Lysine Diisocyanate

Urethane elastomers have been used for decades in biomedical applications because of their wide range of physical properties.1–4 However, their use has been limited to nondegradable matrices synthesized with toluene diisocyanate (TDI) as the hard segment and a variety of polyesters or polyethers as the soft segment. Nevertheless, when these polymers slowly degrade, their degradation product, 2,4-diaminotoluene, tends to be toxic in vivo. Attempts to replace TDI with aliphatic diisocyanates such as 4,4-methylenedicyclohexyl diisocyanate and hexamethylene diisocyanate have met with similar concerns of toxicity, because the diamines liberated during their degradation are still relatively toxic. Yet, except for their toxicity, urethanes possess many attributes that are ideal for biomedical applications. For example, urethane chemistry provides a wide range of synthetic options that can be varied through changing the hard segment (diisocyanate), the polyol, the chain extenders, and/or the ratios in which they are reacted. These modifications in the chemistry can be utilized to affect the mechanical and biological properties of the matrices. Attempts to replace the hard segment of urethanes to obtain nontoxic polymers have met with limited success. This was due either to the contaminants present in the hard segment preparations or to the inherent problems associated with the soft segments.

A study from Zhang J.-Y et al (2019) reported the ability to make non-toxic biodegradable polymers. They showed to make a LDI–glucose polymer that possesses many attributes which are potentially useful in tissue-engineering and other biomedical applications. The authors state that LDI polymerized with glucose yields a matrix that can be foamed in aqueous solutions for use as scaffolds for cell growth. LDI–glucose polymer foam is biodegradable and its degradation products are nontoxic and do not alter the pH of PBS. LDI–glucose foam exhibits physical properties that are suitable for cell growth in vitro. The LDI–glucose polymer is nonimmunogenic and induces minimal foreign body reactions in the form of capsule formation in vivo.

Zhang, J.-Y., Beckman, E. J., Hu, J., Yang, G.-G., Agarwal, S., & Hollinger, J. O. (2002). Synthesis, Biodegradability, and Biocompatibility of Lysine Diisocyanate–Glucose Polymers. Tissue Engineering, 8(5), 771–785. doi:10.1089/10763270260424132

Abstract:

The success of a tissue-engineering application depends on the use of suitable biomaterials that degrade in a timely manner and induce the least immunogenicity in the host. With this purpose in mind, we have attempted to synthesize a novel nontoxic biodegradable lysine diisocyanate (LDI)- and glucose-based polymer via polymerization of highly purified LDI with glucose and its subsequent hydration to form a spongy matrix. The LDI–glucose polymer was degradable in aqueous solutions at 37, 22, and 4°C, and yielded lysine and glucose as breakdown products. The degradation products of the LDI–glucose polymer did not significantly affect the pH of the solution. The physical properties of the polymer were found to be adequate for supporting cell growth in vitro, as evidenced by the fact that rabbit bone marrow stromal cells (BMSCs) attached to the polymer matrix, remained viable on its surface, and formed multilayered confluent cultures with retention of their phenotype over a period of 2 to 4 weeks. These observations suggest that the LDI–glucose polymer and its degradation products were nontoxic in vitro. Further examination in vivo over 8 weeks revealed that subcutaneous implantation of hydrated matrix degraded in vivo three times faster than in vitro. The implanted polymer was not immunogenic and did not induce antibody responses in the host. Histological analysis of the implanted polymer showed that LDI–glucose polymer induced a minimal foreign body reaction, with formation of a capsule around the degrading polymer. The results suggest that biodegradable peptide-based polymers can be synthesized, and may potentially find their way into biomedical applications because of their biodegradability and biocompatibility.